1. Field of the Invention
This invention relates to power door lock circuits for motor vehicles and more specifically to circuits of the type which inhibit locking power door locks when a key is left in the ignition and provides an audible indication when keys are left in the ignition and there is an attempt to exit the vehicle.
2. Description of the Prior Art
In automobiles with power door locks, ignition keys have been locked in vehicles because the power door operator has been able to actuate the power door locks upon exiting from the vehicle, often locking the keys in the vehicle. If this is done with all the windows closed, the operator will be unable to reach in and actuate the unlock switch so that he can retrieve his keys.
In some vehicles, an audible warning is given when keys are left in the vehicle when an attempt is made to leave the vehicle. Such systems generally employ dedicated networks used specifically for providing a warning to the operator that the keys have been left in the ignition switch key receptacle. Usually such systems, besides being costly, require additional electrical circuits and components.
Realizing the problems associated with cost in providing a system which would prevent the power doors from being locked when keys are left in the ignition, a search for various other means which could be integrated into an existing power door lock system was initiated. This search resulted in the improved key and door interlock system of the present invention.